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That post and that site link were from 8 years ago. Lots of reasons for it to not be valid.

08-07-2011 04:00 PM

jaschrumpf

I've got a Newport 28 with the A4 in it, running a 10" 7.4deg Indigo prop. (I think I've remembered all those numbers correctly.) I too only get around 2000 rpm max, but it'll push me at about 6kt or so. Sounds like you're in the same ballpark as I.

For the guy wanting a little more thrust... your prop gets to spinning so fast that it is not really pushing water anymore but acting more like a food processor. If you have checked the timing and carb adjustment you may want to think about adding a fence to your prop blades so they have a little more thrust at lower RPM

04-01-2004 05:51 AM

angiewilson

Atomic 4 is 4 lovers

For the guy with the knock try some Marvelous Mystery Oil in the fuel mix. Add 6-8 oz to 10 gal of fuel, but first just put some right into the spark plug holes.... you will be amazed!

For the guy who was quoted the 4K for the crank.... I''ve got some ocean front property in TN that I can make you a great deal on....You can get a completely upgraded/rebuilt A4 thru Moyers Marine (the guru of the A4) for about $2700.

03-31-2004 05:54 PM

Irwin32

Atomic 4 is 4 lovers

4k for a new crank. I have seen many rebuilt A4s for less than that.

03-30-2004 07:35 AM

sailnaway

Atomic 4 is 4 lovers

I have an Atomic 4 1979 in a Catalina 38 I also have a power prop that gives it a bit more thrust in reverse since Cat38 boats dont back down for nobody. The motor will inly make 2000 rpm at full power. I find it pushes the hull at 6.5 kts at 1500 rpm and gets a fair fuel burn and don''t shake rattle or roll. I was talking to a guy who was getting me some parts and he said the Atomic crank was near $4000 bucks for our friend with the knock fix it fix it now. The reason for the high price is for a couple of grand more you have a new motor marketing people suck. I am switching lube in the motor to full synthetic AMSOIL which I sell flushing the motor and getting rid of all that carbon.Longer oil change periods and engines run cooler.

thanks for your help. that is an excelent web site. I also emailed Don Moyer at Moyer Marine and he said that sounds normal for the RPM, Anyone out there with a 1974 Capital Newport 27'' with an atomic 4 engine. I just wanted to compare and see similarities; and maybe improvements.

10-24-2003 08:44 AM

dpboatnut

Atomic 4 is 4 lovers

I believe it is proper to attribute the source when quoting, and it didn''t come through in the previous post. For the source, see: